The invention relates to a record disk cartridge adapted to be installed for recording operations on a disk drive unit.
Random access disk stores have been used in data processing systems. Such disk stores employ a disk assembly of one or more rigid magnetically coated disks which can be mounted on a disk drive unit for recording and playback of data from the disk surfaces. Often the disks are contained within a cartridge or pack to facilitate handling and storage as well as to protect the surfaces of the disks during installation and removal from the disk drive. The cartridge prevents human contact with the disk surfaces and seals the disk assembly from airborne contaminants. Provision is made to allow the necessary connections to be made with the drive unit, including the introduction of one or more transducers into a transducing proximity to the disk surfaces and the attachment of the disk assembly to a drive shaft for rotation of the disks.
One such cartridge containing a rigid disk has been provided with an access door in its side which is automatically opened when the cartridge is installed on the drive unit to permit transducers contained within the drive unit to be inserted until they lie above the disk surfaces, respectively. When the the disks are up to operational speed, the transducers are loaded towards the disk surfaces until a suitable air bearing is established. Transducing operations then are performed over the disk surfaces in the usual way under control of a transducer actuator mechanism.
As track and bit densities increased and transducer flying heights became correspondingly smaller, it became increasingly important to ensure that the disk surfaces over which the transducers fly on their air bearings are free of contaminating particles which could lead to transducer crashes. The movement in the industry therefore was away from cartridges such as described above and more towards factory sealed data modules containing disks, transducers and either all or part of the transducer actuator mechanism. These modules were provided with a mechanical interface for rotating the enclosed disks and, where necessary, for connecting the remainder of the actuator, and an electrical interface for controlling the transducing operatings on the disks within the module.
At the same time, development of flexible record substrate material was taking place. An advantage of using flexible disks is that, the disk flies over the head in contrast to the reverse as in the case with rigid disks. Accordingly, a noncompliant head mounting can be used and the expensive suspension unit previously required can be dispensed with. Furthermore, flexible disks seem to be less affected by contamination than their rigid counterparts. This it is felt is due to the relatively low mass of the flexible material and its low inertia which enables it to lift over contaminants without causing damage to either transducer or disk surface. This has been found to be the case even for an average disk head operation as low as 10 microinches.
With the availability of thin flexible material, the development of a flexible disk cartridge was undertaken for installation during use of a drive unit containing the disk drive motor and the head actuator mechanism. Apertures are required in the cartridge to permit insertion of the head for accessing the surface of the disk and for connection of the disk to the drive motor. Although problems of contamination are not so great as with rigid disks, the considerable reduction of disk-to-head separation during operation makes it desirable to keep the disk enclosure as free of contaminants as possible. Thus apertures through the enclosure which exposes the disk should be closed when the cartridge is not in use on the drive. This closure prevents damage to the disk caused by operator contact during handling and ingress of at least gross contaminants during such handling, as well as during storage periods.